array_filter
(PHP 4 >= 4.0.6)
array_filter -- Filters elements of an array using a callback
function
Description
array array_filter ( array input [, callback callback])
array_filter() iterates over each value in the input array
passing them to the callback function. If the callback function
returns true, the current value from input is returned into
the result array. Array keys are preserved.
Example 1. array_filter() example
<?php
function odd($var)
{
return($var % 2 == 1);
}
function even($var)
{
return($var % 2 == 0);
}
$array1 = array("a"=>1, "b"=>2,
"c"=>3, "d"=>4, "e"=>5);
$array2 = array(6, 7, 8, 9, 10, 11, 12);
echo "Odd :\n";
print_r(array_filter($array1, "odd"));
echo "Even:\n";
print_r(array_filter($array2, "even"));
?>
The printout of the program above will be:
Odd :
Array
(
[a] => 1
[c] => 3
[e] => 5
)
Even:
Array
(
[0] => 6
[2] => 8
[4] => 10
[6] => 12
)
Users may not change the array itself from the callback
function. e.g. Add/delete an element, unset the array that
array_filter() is applied to. If the array is changed, the
behavior of this function is undefined.
If the callback function is not supplied, array_filter()
will remove all the entries of input that are equal to FALSE.
See converting to boolean for more information.
